Question 430398
Ok, So for functions that are a fraction, the denominator cannot equal zero.
So you solve {{{x^2-3x=0}}} to see what is not allowed, factoring gives you {{{x(x-3)=0}}}, and that gives you {{{x=0}}} and {{{x=3}}}, so x cannot equal 0 or 3. As for how to express this answer 
Domain:({{{-infinity}}},0)U(0,3)U(3,{{{infinity}}})